Vehicle manufacturers of today increasingly focus on improved safety of vehicle occupants. If it appears likely or unavoidable that a vehicle will be involved in a collision situation, safety devices such as airbags may be activated in order to protect the vehicle occupant from the consequences thereof. Current vehicles typically employ accelerometers that measure decelerations acting on the vehicle body in the event of a collision. Radar, lidar, and/or vision-based pre-crash sensing systems are furthermore commonly utilized to deploy safety devices at an early stage in a collision situation, or even before the actual impact. It is also known to activate safety devices in response to detected uncomfortable and/or hazardous vehicle dynamics situations, such as under-steer, over-steer, skidding, emergency braking or evasive maneuvering.
In addition to airbags, safety devices may be represented by reversible restraint systems such as motorized seatbelt retractors and movable support surfaces, e.g., knee padding and movable headrests. The reversible restraint systems are commonly designed to apply a restraining force to the vehicle occupant in a critical situation, and to remove the restraining force when and if the critical situation is over. Additionally, such restraint systems may be intended to provide additional support for bracing a vehicle occupant during uncomfortable vehicle dynamic situations. In most of such cases, there is also an increased risk of an accident occurring even if a collision is not likely.
WO 2008/041904, for instance, discloses a control system for controlling a reversible restraint arrangement for a vehicle occupant. The control system is operable to generate an output signal to control the reversible restraint arrangement if it is determined from the character of the road ahead of the vehicle that activation of the reversible restraint arrangement is required. The output signal is generated if it appears that the vehicle is likely to be involved in a hazardous situation or an uncomfortable dynamic situation. Accordingly, situations in which a reversible restraint system is to be deployed may be detected at an early stage, and hence the reversible restraint system may be applied gradually.
However, although the control system of WO 2008/041904 enables less discomfort or alarm to vehicle occupants by avoiding reversible restraint systems being applied quickly and without warning, the vehicle occupants may still experience discomfort from the reversible restraint systems.